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Windows Server 2025 Windows Server 2025 Security update
Patch Tuesday

KB5065426

KB5065426: Cumulative update for Windows Server, version 2025, September 2025. SMB flaw disclosed; older print clients lose access to updated servers

In short

An SMB elevation-of-privilege flaw is publicly disclosed, and older Windows print clients can no longer print to updated servers. PowerShell 2.0 is also removed.

Does it affect you? Applies to: Devices running Windows Server 2025, build 26100.6584. The listed update package is for x64 systems.

Build
26100.6584
Security
64 fixed · 8 critical
Restart
Required

Microsoft publishes separate notes for this KB for Windows 11.

What changes

Fixes 17 changes

Taskbar

2 items
  • Keyboard focus no longer gets stuck on the taskbar frame after moving backward through taskbar items.1
    This could cause screen readers to say “pane.”
  • Widgets no longer open unexpectedly when keyboard focus moves to them at sign-in.2

Voice Access

  • Voice Access no longer stops responding with the “working on it” error while dictating.3

BitLocker

  • Some devices with BitLocker on removable drives no longer get a blue screen after sleep or hybrid boot.4

Bluetooth

Verified in package
  • Settings no longer stops responding while loading information about Bluetooth devices.5

Boot menu screens

  • Early boot screens, including BitLocker PIN and recovery screens, no longer render slowly.6

Display

  • Some devices no longer get unexpected screen size or window position changes after waking from sleep.7

File Explorer

Verified in package
  • Searching from Home can run even if network drives are disconnected while the search is in progress.8

Input

Verified in package 3 items
  • Voice typing can start from the touch keyboard in the Chinese (Simplified) narrow layout.9
  • Changing pages in the touch keyboard's Symbols section no longer inserts a character into password fields.10
  • Typing in some apps keeps working after disconnecting from a remote desktop session.11

JPG

  • Some images no longer have unexpectedly inverted pixels when read.12
    Fixes certain cases involving CopyPixels.

Memory leak

Verified in package

For: multi-user, multi-lingual, and remote desktop environments

  • Memory use no longer increases due to an Input Service issue that could affect performance.13
    The issue could affect multi-user, multi-lingual, and remote desktop use.

Network

For: new Windows Server 2025 domain controllers

  • New domain controllers no longer always show the network as public.14
    The server checks for a domain controller name before using loopback addresses for LDAP binding.

Print

  • Non-admin users can uninstall printers they added.15

USB

  • Some USB devices no longer disconnect after sleep and stay disconnected until reboot.16

App compatibility (known issue)

For: non-admin users and IT administrators

  • Non-admin users get fewer unexpected permission prompts when some app installers repair or configure apps.17
    The fix reduces the scope of User Account Control prompts for MSI repairs. Admins can add specific apps to an allowlist to disable those prompts.

New features 9 changes

Settings

Verified in package
  • Settings adds a FAQs section with answers about Windows Server setup, performance, and compatibility.18
    Find it under Settings > System > About.

Taskbar

  • Admins can let users unpin selected apps without those apps returning at the next policy refresh.19
    Use the new PinGeneration option in taskbar policies.

Voice Access

Verified in package 2 items
  • Voice Access can highlight its new features and improvements in an in-app guide.20
    Open or dismiss the guide from the settings menu.
  • Voice Access is available in Quick Settings near the clock.21
    Open Quick Settings by selecting the network, volume, or battery icon.

Voice Typing

Verified in package
  • You can choose whether Voice Typing masks profanity with asterisks.22
    Change the Filter profanity switch in Voice Typing settings, opened with Win + H.

Windows Share

3 items
  • You can crop, rotate, and add filters to images in the Windows Share window.23
  • Dragging a local file from File Explorer or the desktop opens a tray of suggested sharing apps.24
    Drop the file on a suggested app or select More to open the Windows Share window.
  • You can add supported sharing apps to the right-click menu for local files.25
    The menu is available in File Explorer and on the desktop.

File server

  • Admins can check whether devices or software might be incompatible with SMB security changes before deploying them.26
    Auditing is enabled for SMB Server signing and SMB Server EPA compatibility.

Improvements 4 changes

Settings

Verified in package 2 items
  • The printer rename dialog now matches the Windows Server look and feel.27
    The dialog is under Settings > Bluetooth & devices > Printers & scanners.
  • Mouse settings are easier to find, and more pointer options are available in Settings.28
    Options include mouse pointer speed, pointer precision, the mouse indicator, pointer trails, and hover activation time.

Microsoft Management Console (MMC)

  • Selected items are easier to see in MMC, including when contrast modes are on.29

Print

Verified in package

For: organizations with older print clients and updated print servers

  • Updated print servers no longer support printing from some older Windows clients.30
    Printing components move from MSVCRT to Universal C Runtime Library. Clients older than Windows 10, version 2004, or Windows Server, version 2004 (build 19041), fail to print to updated Windows 11, versions 24H2 or 25H2, and Windows Server 2025 servers. The source recommends upgrading clients to Windows 10, version 22H2 or newer, or using pre-Windows Server 2025 print servers.

Removal 1 change

PowerShell 2.0

For: users of older scripts or tools

  • PowerShell 2.0 is no longer included. Most users are unaffected, but older scripts or tools that depend on it need updating.31
    PowerShell 5.1 and PowerShell 7.x remain available and supported.

Known issues

  1. Open Affects: Organizations and IT administrators

    Active Directory Replication

    A Windows Server 2025 domain controller with the schema master role might allow duplicate schema entries, causing Active Directory replication to fail.32

    Workaround status No workaround yet

    Microsoft has not published a manual workaround for this issue yet. Monitor release health until a resolving update is available.

  2. Open Affects: Organizations and IT administrators

    Directory synchronization (DirSync)

    Apps using directory synchronization might incompletely sync on-premises security groups with more than 10,000 members.33

    Workaround status No workaround yet

    Microsoft has not published a manual workaround for this issue yet. Monitor release health until a resolving update is available.

  3. Open Affects: Organizations and IT administrators

    SMBv1 protocol connectivity

    Connections to shared files and folders using SMBv1 over NetBIOS over TCP/IP might fail if either the client or server has the September 2025 security update.34

    Workaround status No workaround yet

    Microsoft has not published a manual workaround for this issue yet. Monitor release health until a resolving update is available.

  4. Open Affects: Organizations and IT administrators

    PSDirect connections failing in hotpatched devices

    PowerShell Direct connections might fail at times on hotpatched devices when the host and guest virtual machines are not both fully updated.35

    Workaround status No workaround yet

    Microsoft has not published a manual workaround for this issue yet. Monitor release health until a resolving update is available.

Technical details

Data sheet · Security · Downloads · Components Click to collapse or expand

Data sheet

Released
2025-09-09
Classification
Security Updates
Type
Cumulative update
Restart
Required
Replaces
KB5063878, KB5064489, KB5062553, KB5060842
+9 earlier KB5058411, KB5055523, KB5053598, KB5051987, KB5050009, KB5048667, KB5046617, KB5043080, KB5044284
Replaced by
KB5068221
VersionBuildChannel
2025 26100.6584 General availability

Security

64 vulnerabilities fixed
8 critical 55 important 1 moderate
VulnerabilitySeverityCVSS
CVE-2025-54918
Windows NTLM Elevation of Privilege Vulnerability
 Critical 8.8
CVE-2025-53800
Windows Graphics Component Elevation of Privilege Vulnerability
 Critical 7.8
CVE-2025-55224
Windows Hyper-V Remote Code Execution Vulnerability
 Critical 7.8
CVE-2025-55228
Windows Graphics Component Remote Code Execution Vulnerability
 Critical 7.8
CVE-2025-55236
Graphics Kernel Remote Code Execution Vulnerability
 Critical 7.3
CVE-2025-48807
Windows Hyper-V Remote Code Execution Vulnerability
 Critical 6.7
CVE-2025-55226
Graphics Kernel Remote Code Execution Vulnerability
 Critical 6.7
CVE-2025-53799
Windows Imaging Component Information Disclosure Vulnerability
 Critical 5.5
CVE-2025-55234
Windows SMB Elevation of Privilege Vulnerability
 Important 8.8

The table lists the 9 exploited, publicly disclosed or critical vulnerabilities. See all 64 vulnerabilities →

Updated components

10,929 files changed since the previous update for the same versions.

Top changed componentsFiles
Settings150
Printing63
Graphics and display55
Bluetooth54
Networking52
Remote Desktop46
Audio43
Hyper-V and virtualization43
Security and sign-in41
.NET networking38
Windows Update32
File Explorer and shell29

Verified in package: changed files confirm Bluetooth, File Explorer, Input, Memory leak, Settings, Voice Access, Voice Typing, Print.

Sources

Updated
Cited passages from Microsoft's official notes (35)
  1. 1. Fixed: When using Tab and Shift + Tab to move keyboard focus around the taskbar, if you go backwards at least once you can get keyboard focus stuck on the taskbar frame, which could lead screen readers to just say “pane.” support.microsoft.com
  2. 2. Fixed: On login, the keyboard focus might unexpectedly be set to widgets in the taskbar, which can cause widgets to open. support.microsoft.com
  3. 3. Fixed: Voice access might stop responding with error “working on it” when dictating. support.microsoft.com
  4. 4. This update addresses an issue where devices with BitLocker on removable drives could encounter a blue screen error after resuming from sleep or hybrid-booting. support.microsoft.com
  5. 5. Settings might stop responding when loading information about Bluetooth devices. support.microsoft.com
  6. 6. This update addresses the issue where early boot screens, such as BitLocker PIN, BitLocker Recovery key, and boot menu screens, render slowly. support.microsoft.com
  7. 7. Unexpected changes to screen size and window position might occur after waking from sleep for some devices. support.microsoft.com
  8. 8. If you have disconnected network drives while conducting a search from Home, it might prevent searches from executing and you remain on Home. support.microsoft.com
  9. 9. Voice typing won't start from the touch keyboard when using the Chinese (Simplified) narrow layout. support.microsoft.com
  10. 10. When using the Symbols section of the touch keyboard, pressing the key to change pages might unexpectedly insert a character into password fields. support.microsoft.com
  11. 11. Typing in some apps might stop working after disconnecting from a remote desktop session. support.microsoft.com
  12. 12. When using CopyPixels the pixels may be unexpectedly inverted in certain cases. support.microsoft.com
  13. 13. This update addresses an issue in the Input Service that causes increased memory usage, potentially impacting performance in multi-user, multi-lingual, and remote desktop usage. support.microsoft.com
  14. 14. This update addresses an issue where Windows Server 2025 always shows the network as "public" on new domain controllers. support.microsoft.com
  15. 15. Non-admin users can't uninstall printers that they’ve added. support.microsoft.com
  16. 16. Certain USB devices might become disconnected after sleep, until you reboot your PC. support.microsoft.com
  17. 17. Addresses an issue that caused non-admin users to receive unexpected User Account Control (UAC) prompts when MSI installers perform certain custom actions. support.microsoft.com
  18. 18. It covers topics like system setup, performance, and compatibility—all in one place. support.microsoft.com
  19. 19. Admins can configure taskbar policies so users can unpin specific apps, ensuring they are not repinned during the next policy refresh. support.microsoft.com
  20. 20. Voice access now includes an in-product experience that highlights new features and improvements. support.microsoft.com
  21. 21. You can find voice access under Accessibility in Quick Settings at the lower-right corner of your screen near the clock. support.microsoft.com
  22. 22. You control the profanity filter. When you turn it on, it masks profanity with asterisks. support.microsoft.com
  23. 23. Make last-minute edits such as cropping, rotating, and adding filters to images shared through the Windows Share window. support.microsoft.com
  24. 24. When you drag a local file from File Explorer or your desktop, a tray appears at the top of your screen. support.microsoft.com
  25. 25. Add apps that support sharing directly to the right-click menu for local files in File Explorer or on the desktop. support.microsoft.com
  26. 26. This allows customers to assess their environment and identify any potential device or software incompatibility issues before deploying the hardening measures that are already supported by SMB Server. support.microsoft.com
  27. 27. The dialog to rename your printer under Settings > Bluetooth & devices > Printers & scanners now matches the Windows Server look and feel. support.microsoft.com
  28. 28. Mouse settings are now easier to access under Settings > Accessibility > Mouse and Mouse pointer and touch, with no need to open Control Panel. support.microsoft.com
  29. 29. Improved the colors used in MMC when items are selected, both generally, and when contrast modes are enabled. support.microsoft.com
  30. 30. As a result of this change, print clients running versions of Windows prior to Windows 10, version 2004 and Windows Server, version 2004 (Build number 19041) will intentionally fail to print to remote print servers running Windows 11, versions 24H2 or 25H2, and Windows Server 2025, that have installed this update, or later updates. support.microsoft.com
  31. 31. Starting in September 2025, Windows Server 2025, will no longer include Windows PowerShell 2.0. support.microsoft.com
  32. 32. Active Directory domain controllers (DC) running on Windows Server 2025 and also running the schema master Flexible Single Master Operation (FSMO) role, will allow duplicate entries in attributes of schema objects. support.microsoft.com
  33. 33. Applications that use the Active Directory directory synchronization (DirSync) control for on-premises Active Directory Domain Services (AD DS), such as when using Microsoft Entra Connect Sync, can result in incomplete synchronization of large AD security groups exceeding 10,000 members. support.microsoft.com
  34. 34. After installing the Windows update released on or after September 9, 2025, you might fail to connect to shared files and folders using the Server Message Block (SMB) v1 protocol on NetBIOS over TCP/IP (NetBT). support.microsoft.com
  35. 35. These devices might experience failures with PowerShell Direct (PSDirect) connections when the host and guest virtual machines (VMs) are both not fully updated. support.microsoft.com
Checked automatically: 8 of 8 checks passed, 35 quoted passages · compared with Microsoft's page on Oct 20, 2026
  • Quotes found in the official pages: passed
  • Numbers found in the sources: passed
  • Vulnerabilities from the dossier only: passed
  • Links to allowed domains only: passed
  • Every official change covered: passed
  • Readable plain text: passed
  • Changes confirmed by the file list: passed
  • Sources agree: passed

A second AI read the text against the sources: correctness 4/5, clarity 4/5, completeness 4/5. How we work

Published by The Update Bureau. Written with AI from Microsoft's own documents, checked by rules and a second AI. How we work · Report a mistake